title: Effect of subdermal 1,444-nm pulsed neodymium-doped yttrium aluminum garnet laser on the nasolabial folds and cheek laxity.
abstract: BACKGROUND
  Wrinkle formation usually accompanies skin aging. In particular, accentuated nasolabial folds and loss of elasticity are early signs of skin aging. The use of 1,444-nm pulsed neodymium-doped yttrium aluminum garnet (Nd:YAG) lasers has increased in popularity.
  
  
  OBJECTIVE
  To evaluate the safety and efficacy of a novel 1,444-nm pulsed Nd:YAG laser in the treatment of NLF and cheek laxity using subdermal laser therapy.
  
  
  METHODS
  Ten Korean patients with moderate to severe NLF were enrolled. Each received a single treatment session with a 1,444-nm Nd:YAG laser. Two blinded physicians evaluated clinical improvement by rating comparative photographs on a 5-point scale. Efficacy was also assessed by measuring elasticity and roughness. Skin biopsies were performed on five volunteers before treatment and 3 months after treatment.
  
  
  RESULTS
  The 1,444-nm Nd:YAG laser effectively promoted clinical improvement of NLF and cheek laxity (p < .05). Significant differences in elasticity and roughness were observed (p < .05). Epidermal proliferation was stimulated as demonstrated by increases in epidermal thickness and Ki-67 expression (p < .05). Quantitative image analyses of pre- and post-treatment biopsies revealed that collagen fibers increased from baseline (p > .05). Transforming growth factor beta and heat shock protein-70 messenger RNA levels quantified using real-time reverse transcriptase polymerase chain reaction increased significantly from baseline (p < .05).
  
  
  CONCLUSIONS
  The 1,444-nm Nd:YAG laser is an effective treatment modality with minimal complications for the treatment of NLF and cheek laxity, but further research with a larger group of patients is needed to confirm these findings.
authors.affiliation: Department of Dermatology and Cutaneous Biology Research Institute, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Soo Hyun
authors.initials: SH
authors.lastname: Lee
authors.forename: Mi Ryung
authors.initials: MR
authors.lastname: Roh
authors.forename: Jin Young
authors.initials: JY
authors.lastname: Jung
authors.forename: Hyunjoong
authors.initials: H
authors.lastname: Jee
authors.forename: Kyoung Ae
authors.initials: KA
authors.lastname: Nam
authors.forename: Kee Yang
authors.initials: KY
authors.lastname: Chung
mesh_terms: D002610:Cheek / Q000502:physiology / Q000528:radiation effects*; D003094:Collagen / Q000378:metabolism; D004867:Equipment Design; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism; D006801:Humans; D053844:Lasers, Solid-State; D060052:Nasolabial Fold / Q000502:physiology* / Q000528:radiation effects*; D015595:Skin Aging / Q000528:radiation effects*; D016212:Transforming Growth Factor beta / Q000378:metabolism
chemical_list: D018840:HSP70 Heat-Shock Proteins; D016212:Transforming Growth Factor beta; D003094:Collagen